kvm: Configure and start SSH server (#421)

Step 1 actually is a configuration step, it does not enable SSH. Besides that, the server has to be started.

source/clear-linux/get-started/virtual-machine-install/kvm.rst

@@ -108,7 +108,7 @@ SSH access into the virtual machine
 To interact with the |CL| VM through SSH instead of the console it was
 launched from, follow these steps.
 
-#. Enable SSH in the |CL| VM:
+#. Configure SSH in the |CL| VM to allow root login:
 
    .. code-block:: bash
 
@@ -116,6 +116,12 @@ launched from, follow these steps.
         PermitRootLogin yes
         EOF
 
+#. Start SSH server in the |CL| VM:
+
+   .. code-block:: bash
+
+      systemctl start sshd
+
 #. From the host, SSH into the |CL| VM.  The port number ``10022`` is defined
    in the ``start_qemu.sh`` script.